Gas-compressor



Patented Apr. l1, 1893 e. LAWSON. GAS COMPRESSOR.

(No Model.)

UNITED STATES PATENT OFFICE.

ENOCH LAWSON, OF SAN FRANCISCO, CALIFORNIA.

GAS-COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 495,348, dated April 11, 1893.

Application filed June 30, 1891. Serial No. 3981067. (No model.)

To @ZZ whom it may concern,.- Be it known that I, ENOOH LAWSON, a citizen of the United States, residing in the city `and county of San Francisco, State of Calicompressing air, gas, or vapor, and itconsists of stationary and movable cylinders, a movable piston operating in the stationary cylinder, and a stationary piston operating in the movable cylinder, and in certain details of construction which will be more fully explained by reference to the accompanying drawings, in which- Figure 1 is a vertical section through my compressor showing the piston down. Fig. 2 is a vertical section taken at right angles to Fig. 1, the piston being on its up stroke.

A is the main exterior cylinder, and B is the interior movable cylinder which is concentric with the main cylinder and has apiston Cformed upon its lower end, or connected therewith, and fitting the interior of the main cylinder. A head E is fixed to the lower end of this cylinder, and the piston rod F is secured to this head.

D D are inlet valves opening through the,v

G is an inlet pipe, and H is a Valve of any y suitable or well known description, which opens into the main cylinderAat the bottom. When the cylinder B and the piston C are forced upwardly by the movement of the piston rod F, the valve I-I will open and admit the gas or vapor which is to be compressed, into the lower part of the main cylinder.

I have in the present drawings shown the cylinders arranged vertically, and therefore describe the positions and movements of the parts with reference to such an arrangement, but it will be manifest that a horizontal arrangement can be made if more convenient, the operation being essentially the saine. Upon the upperend of the cylinderA is fitted 'a cap I and the cylinder J extends downwardly from this cap and concentric with the cylinders A and B. Upon the exterior of the cylinder J, at the lower end, is a piston K which iits within the movable cylinder B.

L is a valve opening upwardly from the cylinder B into the cylinder J. This valve is shown at present with the guide stem M, and the coil spring N which insures the valve being closed quickly.

O is the pipe leading from the upper end of the cylinder J and delivering the compressed air or gas to any desired point. Around this pipe, upon the upper end of the apparatus, is a Water tank P. The cylinder .J is cast with an annular space or channel in its walls, and water is admitted from a supply pipe Q to circulate within this space, and counteract the tendency to heat which arises in all cases of compression of air or gas. The

Water is admitted to the space around the cylinder through the pipe Q which leads into the annular chamber, opening near the bottom of the chamber so as to deliver the cold Water at that point. The water rises in this annular chamber through channel Q into the tank or receiver P at the top, and escapes through an overflow pipe R, thus keeping up a constant circulation which will prevent the undue heating of the cylinder. The first co'mpression which takes place withinl the exterior cylinder is so small that not a great deal of heat is developed, and I have not in the present case shown any Water chamber around this cylinder, but if found necessary or desirable itis manifest that such a chamber can be employed.

The operation of my device will then be as followsz-When the machine is set in motion, the piston rod F forces the piston C and the cylinder B upward. The piston C, moving within the cylinder A, produces a vacuum and the valve H is opened by the exterior pressure through the pipe G to admit the air or gas into the lower part of the cylinder A and beneath the piston C. The valves D remain closed and the valve L will be opened so that any air or gas within the piston B Will be forced through it into the cylinder J. When the piston C returns o n its downward stroke, the valve H closes and the air or gas which has been drawn into the cylinder A will then open the valves D and pass into the cylinder B, being compressed by this operation to a IOO degree which depends upon the relative proportions of the cylindersA and B. Upon the upward movement of the cylinder B the air or gas which has been compressed into it will then be forced through the valve L and into the stationary cylinder J which carries the stationary piston K. The cylinder B, in its upward movement, moves over this piston K which thus acts to force the air or gas in the cylinder B, through `the valve L which is opened upwardly by the pressure, and into the still smaller cylinder J. With each reciprocation of the piston C and cylinder B this operation is repeated, and the compressed air or gas is forced outwardly through the delivery pipe O. The downward movement of the piston C and the cylinder B is assisted by the small portion of compressed air or gas which may remain in the upper part of the cylinder B at the termination of the stroke, and the upward movement oi' the piston is correspondingly assisted by such pressure of the air or gas as may be in the lower part of the cylinder.

When this apparatus is used in connection with ice machines for the purpose of condensing the gas which is used for freezing purposes, there will be a certain amount of pressure at all times through the pipe G into the lower part of the larger cylinder which will thus assist in the upward movement of its piston and the cylinder B.

In order to equalize the pressure in the cylinder A, and exterior to the cylinders B and J, and prevent any condensationin this portion,

I have shown an equalizing pipe S which con-` nects the feed pipe Gwith the cylinder A at a point above the piston C. This prevents any useless condensation of air or gas in this portion of the cylinder.

T is a small equalizing pipe connecting the spaces above and below the piston C, and having a cock at U which may be opened when the apparatus is to be started, and there is already a considerable pressure within the cylinders B and J. To make this more clear it may be stated that when the ammonia vapor is being pumped continuously, it reaches the apparatus in a comparatively cool state, and the first compression in the outer cylinder does not exceed about ten pounds. If the pump is stopped, the heat generated by cornpression expands the Vapor so that its pressure amounts to sixty pounds or more, and the piston being in the position shown in Fig. 2, it is impossible to start the pump against such a pressure iri the large cylinder. By opening the cock U, this pressure below the piston is relieved and the pump has at rst only to act upon the Vapor within the smaller cylinder, which it is capable-of doing. As soon as the pump is fairly started the vapor arriving will be cool and at a low pressure, and the cock U is closed so that the whole apparatus is at work.V

After the machinery has been started, the valve U may be closed, and the operation will then proceed as before described.

In order to properly lubricate the pistons C and K I have shown an oil pipe V which passes through the cap or upper portion I, thence downwardly throughtheannularspacearound the cylinderJ so that oil which flows through this pipe may be delivered into a groove or channel W which is made around the piston K. The oil is distributed within this channel, and thus thoroughly lubricates the interior of the cylinder B as it reciprocates over the piston. From one side of this channel W, a pipe X leads outwardly through the side of the cylinder B and down to a point where 1t opens into a channel Y which surrounds the piston C, and in this manner the overiiow from the channel W passing through the pipe X is delivered into the channel Y thus lubricating both pistons automatically.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent,V is- 1. In a compressor, the stationary and movble cylinders concentric with each other having a supply pipe and valves, in combination with the equalizing pipe S connecting the supply pipe with the space in the main cylinder above the piston, and the equalizing pipe T connecting with the spaces above and below the main piston and provided with a cock or valve by which the pressure below the piston is relieved when the compressor is to be started against a high pressure, substantially as herein described.

2. In a compressing apparatus, an exterior main cylinder, a piston reciprocating therein and connected with a piston rod passing through a stuffing-box in the lower cylinder head, a cup-shaped cap fixed to the top of the cylinder with the concavity presented thereto, a cylinder extending downward from the center of this cap with a fixed piston formed upon the exterior of its lower end,a cylinder fixed to the ltop of the main piston reciprocating therewith, and iitting over the stationary piston, an annular open channel surrounding the stationary piston, an oil conducting pipe passingdown within the inner stationary cylinder and communicating with the annular channel,a second pipe connecting with said channel through the top of the intermediate cylinder, passing down outside of it and connecting with an annular channel made about the main piston, whereby the latter is lubricated by the overflow from the stationary piston, substantially as herein described.

In witness whereof I have hereunto set my hand.

ENOCH LAWSON.

Witnesses:

S. I-I. NoURsE, J. A. BAYLEss.

ICO 

